U.S. patent application number 11/540977 was filed with the patent office on 2008-04-03 for method of capturing fingerprint image.
This patent application is currently assigned to WISON TECHNOLOGY CORP.. Invention is credited to Chap-Meng Bee, Jer-Chuan Huang.
Application Number | 20080080751 11/540977 |
Document ID | / |
Family ID | 39261258 |
Filed Date | 2008-04-03 |
United States Patent
Application |
20080080751 |
Kind Code |
A1 |
Bee; Chap-Meng ; et
al. |
April 3, 2008 |
Method of capturing fingerprint image
Abstract
A method of capturing a fingerprint image comprises the steps
of: (1) putting a finger in front of a camera; (2) determining
whether a fingerprint is located within an image capture region of
the camera; (3) if "No", adjusting the position of the camera or
finger and returning to the step 2; (4) if "Yes", capturing a
fingerprint image; (5) transforming the fingerprint image from a
colored fingerprint image into a gray scale fingerprint image; (6)
binarizing the gray scale fingerprint image; (7) thinning the gray
scale fingerprint image; and (8) extracting a fingerprint template.
By the use of aforesaid steps, the fingerprint image can be
captured by the camera.
Inventors: |
Bee; Chap-Meng; (Jhunan
Township, TW) ; Huang; Jer-Chuan; (Yijhu Township,
TW) |
Correspondence
Address: |
TROXELL LAW OFFICE PLLC
SUITE 1404, 5205 LEESBURG PIKE
FALLS CHURCH
VA
22041
US
|
Assignee: |
WISON TECHNOLOGY CORP.
|
Family ID: |
39261258 |
Appl. No.: |
11/540977 |
Filed: |
October 2, 2006 |
Current U.S.
Class: |
382/124 |
Current CPC
Class: |
G06K 9/00912 20130101;
G06K 9/00013 20130101 |
Class at
Publication: |
382/124 |
International
Class: |
G06K 9/00 20060101
G06K009/00 |
Claims
1. A method of capturing a fingerprint image comprising the steps
of: (1) putting a finger in front of a camera; (2) determining
whether a fingerprint is located within an image capture region of
said camera; (3) if "No", adjusting a position of said camera or
finger and returning to said step 2; (4) if "Yes", capturing a
fingerprint image; (5) transforming said fingerprint image from a
colored fingerprint image into a gray scale fingerprint image; (6)
binarizing said gray scale fingerprint image; (7) thinning said
gray scale fingerprint image; and (8) extracting a fingerprint
template, wherein said steps constitute said method of capturing
said fingerprint image by said camera.
2. A method of capturing a fingerprint image of claim 1, wherein
said camera is a CMOS-based camera.
3. A method of capturing a fingerprint image of claim 1, wherein
said camera is a CCD-based camera.
4. A method of capturing a fingerprint image of claim 1, wherein
said camera captures said fingerprint image by a fixed focus.
5. A method of capturing a fingerprint image of claim 1, wherein
said camera captures said fingerprint image by an automatic
adjustment mechanism, which comprises AE (Auto Exposure), AF (Auto
Focus) and AWB (Auto White Balance).
6. A method of capturing a fingerprint image of claim 1, wherein
said image capture region has an image capture frame formed
therein, and said image capture frame is in the shape of a circle,
a rectangle, a square, or an irregular.
7. A method of capturing a fingerprint image of claim 1, wherein
said image capture region is composed of a plurality of positioning
dots, and can be chosen by a picking method
8. A method of capturing a fingerprint image of claim 1, wherein
said image capture region is composed of a plurality of positioning
symbols.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method of capturing a
fingerprint image, and more particularly to a fingerprint image
capture method applicable to an apparatus such as a notebook
computer, a mobile phone, or the like that equips with a video
camera or a web camera for identity recognition.
BACKGROUND OF THE INVENTION
[0002] With the development of technology, the identity recognition
nowadays is always an extremely concerned issue in the fields of
criminal investigation, residence, factory, or commerce. There are
several ways to recognize the identity. The utilization of
biometric recognitions is fairly common in recognizing someone's
identity since every individual has unique fingerprints and irises.
Besides, the fingerprint recognition is a more precise technique
among the biometric recognitions.
[0003] Generally speaking, a fingerprint capture device must be
utilized in the fingerprint recognition to read the fingerprint,
and the read fingerprint data are compared with the existing
fingerprint data. The follow-up actions can be performed only when
the comparison result shows that they are matched. On the contrary,
the follow-up actions can not be performed if the comparison result
shows that they are not matched. In this regard, the data security
can be thus promoted.
[0004] No matter what field the fingerprint recognition is applied,
the utilization of the external fingerprint capture device is
unavoidable. Besides, there are many portable electronic products
nowadays to achieve the purposes of inputting, processing and
storing data, and they are also equipped with cameras for capturing
images. Nevertheless, these cameras of these electronic products
are only designed for photographing scenery. If it is desired to
add the identity recognition systems to these electronic products,
the additional fingerprint capture device still must be added
thereto. Thus, it is extremely inconvenient.
[0005] In view of the foregoing description, the motive of the
present invention is to provide the general public with a method of
capturing a fingerprint image effectively by a camera instead of a
fingerprint capture device to provide the electronic product that
equips with the camera with the function of identity recognition
for promoting security.
SUMMARY OF THE INVENTION
[0006] It is a major object of the present invention to provide a
method of capturing a fingerprint image effectively by a camera
instead of a fingerprint capture device.
[0007] It is a minor object of the present invention to provide a
method of capturing a fingerprint image by a camera of an
electronic product so as to promote security effectively.
[0008] In order to achieve the above-mentioned object, a method of
capturing a fingerprint image is comprised of the steps of:
[0009] (1) putting a finger in front of a camera;
[0010] (2) determining whether a fingerprint is located within an
image capture region of the camera;
[0011] (3) if "No", adjusting the position of the camera or finger
and returning to the step 2;
[0012] (4) if "Yes", capturing a fingerprint image;
[0013] (5) transforming the fingerprint image from a colored
fingerprint image into a gray scale fingerprint image;
[0014] (6) binarizing the gray scale fingerprint image;
[0015] (7) thinning the gray scale fingerprint image; and
[0016] (8) extracting a fingerprint template.
[0017] By the use of aforesaid steps, the fingerprint image can be
captured by the camera.
[0018] The aforementioned objects and advantages of the present
invention will be readily clarified in the description of the
preferred embodiments and the enclosed drawings of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a flow diagram showing the main framework of the
present invention.
[0020] FIG. 2 is a schematic diagram showing that the present
invention is applied to a mobile phone.
[0021] FIG. 3 is a schematic diagram showing that the position of
the fingerprint is determined non-automatically.
[0022] FIG. 4 is a schematic diagram showing that the position of
the fingerprint is determined automatically.
[0023] FIG. 5 is a schematic diagram showing the fingerprint
template of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Referring to FIG. 1, a flow diagram of the main framework of
the present invention is shown. The method of capturing a
fingerprint image comprises the steps of:
[0025] (1) putting the finger in front of a camera;
[0026] (2) determining whether a fingerprint is located within an
image capture region;
[0027] (3) if "No", adjusting the position of the camera or finger
and returning to the step 2;
[0028] (4) if "Yes", capturing a fingerprint image;
[0029] (5) transforming the fingerprint image from a colored
fingerprint image into a gray scale fingerprint image;
[0030] (6) binarizing the gray scale fingerprint image;
[0031] (7) thinning the gray scale fingerprint image; and
[0032] (8) extracting a fingerprint template.
[0033] In accordance with the above-mentioned steps, the
fingerprint image is captured by a camera instead of a fingerprint
capture device.
[0034] So far, quite a few electronic products, for example, mobile
phones, digital camera, notebook computer, and so on, are equipped
with video cameras or web cameras. For the purpose of explanation,
this preferred embodiment of the present invention is exemplified
by the mobile phone. Referring to FIGS. 2 and 3 simultaneously,
after turning on the mobile phone, and if it is desired to read the
data stored into the mobile phone, a display screen of the mobile
phone shows an image capture region 10 inside which an image
capture frame is formed. Besides, the image capture frame is in the
shape of, for example, a circle, a rectangle, a square, or an
irregular. In addition, the image capture frame may be
alternatively composed of positioning dots or symbols. For the
purpose of confirming the user's identity, the user must put his
finger on a location in front of the camera first, and then
determine whether the finger is located within the image capture
region 10 through the display screen, as shown in FIG. 3, so as to
complete the initial positioning. If the finger is not completely
located within the image capture region 10, either the finger or
the mobile phone must be adjusted until the finger is located
within the image capture region 10. After the finger is located in
the image capture region 10, the image capture region 10 notices
the user by showing different colors. For example, the image
capture region 10 may be changed from a red color to a green color.
Alternatively, the image capture region 10 may be chosen by a
picking method. At this moment, for the purpose of capturing a
fingerprint image, the camera is in an auto-adjustment mode that
provides the functions of AE (Auto Exposure), AF (Auto Focus) and
AWB (Auto White Balance). Referring further to FIG. 4, the camera
captures a complete fingerprint image only when the borders of the
fingerprint image are detected to be indeed located on bilateral
blank portions A and B and an upper blank portion C of the image
capture region 10. In other words, the complete fingerprint image
is not captured until the detailed positioning is completed.
[0035] Furthermore, the captured colored fingerprint image is
transformed into a gray scale fingerprint image by the internal
program of the mobile phone. Next, the gray scale fingerprint image
is binarized, and the binarized gray scale fingerprint image is
then thinned. Next, a set of fingerprint minutiae, called template,
is extracted from the thinned fingerprint image. The data structure
of the minutia is indicated by (X, Y, .theta.), wherein (X, Y) are
two-D planar coordinates of the fingerprint minutia, and .theta. is
the direction angle of the fingerprint minutia. After obtaining the
fingerprint template, the fingerprint template can be stored in the
mobile phone. Alternatively, this fingerprint template can be
optionally further compared with the enrolled fingerprint data,
which are stored in the mobile phone before, so that the data
stored in the mobile phone are accessible only when the comparison
result shows that they are matched entirely. Accordingly, the data
security can be thus promoted.
[0036] In accordance with foregoing description, the method of the
present invention has the following advantages:
[0037] 1. The purpose of capturing the fingerprint image can be
achieved by using the built-in camera of the apparatus directly
such that it is very convenient and cost-saving since no additional
fingerprint capture device is required.
[0038] 2. The data stored in the electronic product, which is
equipped with the camera, can be more secure.
[0039] In summary, the present invention indeed achieves the
anticipated objects by disclosing a method of capturing a
fingerprint image, in which the fingerprint image is captured by
the camera directly and the captured fingerprint image transformed
so as to extract a fingerprint template therefrom for performing an
authentication such that the data stored in the electronic product,
which equips with the camera, can be more secure. Accordingly, the
present invention satisfies the requirement for patentability and
is therefore submitted for a patent.
[0040] While the preferred embodiment of the invention has been set
forth for the purpose of disclosure, modifications of the disclosed
embodiment of the invention as well as other embodiments thereof
may occur to those skilled in the art. Accordingly, the appended
claims are intended to cover all embodiments, which do not depart
from the spirit and scope of the invention.
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